Journal of Molecular Evolution

, Volume 60, Issue 2, pp 257–267

Evolution of Plant-Like Crystalline Storage Polysaccharide in the Protozoan Parasite Toxoplasma gondii Argues for a Red Alga Ancestry

Authors

  • Alexandra Coppin
    • Laboratoire de Chimie BiologiqueUniversité des Sciences et Technologies de Lille
  • Jean-Stéphane Varré
    • Laboratoire d’Informatique Fondamentale de LilleUniversité des Sciences et Technologies de Lille
  • Luc Lienard
    • Laboratoire de Chimie BiologiqueUniversité des Sciences et Technologies de Lille
  • David Dauvillée
    • Laboratoire de Chimie BiologiqueUniversité des Sciences et Technologies de Lille
  • Yann Guérardel
    • Laboratoire de Chimie BiologiqueUniversité des Sciences et Technologies de Lille
  • Marie-Odile Soyer-Gobillard
    • Laboratoire Arago, Observatoire océanologiqueUniversité Paris VI
  • Alain Buléon
    • Institut National de la Recherche Agronomique Rue de la Géraudiére
  • Steven Ball
    • Laboratoire de Chimie BiologiqueUniversité des Sciences et Technologies de Lille
    • Laboratoire de Chimie BiologiqueUniversité des Sciences et Technologies de Lille
Article

DOI: 10.1007/s00239-004-0185-6

Cite this article as:
Coppin, A., Varré, J., Lienard, L. et al. J Mol Evol (2005) 60: 257. doi:10.1007/s00239-004-0185-6

Abstract

Single-celled apicomplexan parasites are known to cause major diseases in humans and animals including malaria, toxoplasmosis, and coccidiosis. The presence of apicoplasts with the remnant of a plastid-like DNA argues that these parasites evolved from photosynthetic ancestors possibly related to the dinoflagellates. Toxoplasma gondii displays amylopectin-like polymers within the cytoplasm of the dormant brain cysts. Here we report a detailed structural and comparative analysis of the Toxoplasma gondii, green alga Chlamydomonas reinhardtii, and dinoflagellate Crypthecodinium cohnii storage polysaccharides. We show Toxoplasma gondii amylopectin to be similar to the semicrystalline floridean starch accumulated by red algae. Unlike green plants or algae, the nuclear DNA sequences as well as biochemical and phylogenetic analysis argue that the Toxoplasma gondii amylopectin pathway has evolved from a totally different UDP-glucose-based metabolism similar to that of the floridean starch accumulating red alga Cyanidioschyzon merolae and, to a lesser extent, to those of glycogen storing animals or fungi. In both red algae and apicomplexan parasites, isoamylase and glucan–water dikinase sequences are proposed to explain the appearance of semicrystalline starch-like polymers. Our results have built a case for the separate evolution of semicrystalline storage polysaccharides upon acquisition of photosynthesis in eukaryotes.

Keywords

T . gondii Plant-like metabolism Amylopectin Floridean starch Evolutionary origin Glucan water dikinase Isoamylase Rhodophyte

Copyright information

© Springer Science+Business Media, Inc. 2005